///////////////////////////////////////////////////////////////////////////////
//
// branched from:
//      FreeBSD 7.0-RELEASE
//      $FreeBSD: src/lib/libc/stdlib/getopt_long.c,v 1.15 2006/09/23 14:48:31 ache Exp $
//
///////////////////////////////////////////////////////////////////////////////

/*
 * Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */
/*-
 * Copyright (c) 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Dieter Baron and Thomas Klausner.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "libplatform/impl.h"

namespace mp4v2
{
    namespace platform
    {
        namespace prog
        {

            ///////////////////////////////////////////////////////////////////////////////

#define GNU_COMPATIBLE
#define REPLACE_GETOPT

            namespace
            {
                void warnx( const char *format, ... )
                {
                    va_list ap;
                    va_start( ap, format );
                    vfprintf( stderr, format, ap );
                    va_end( ap );
                    fprintf( stderr, "\n" );
                }
            }

            ///////////////////////////////////////////////////////////////////////////////

#ifdef REPLACE_GETOPT
            int   opterr = 1;    /* if error message should be printed */
            int   optind = 1;    /* index into parent argv vector */
            int   optopt = '?';  /* character checked for validity */
            int   optreset;      /* reset getopt */
            const char *optarg;  /* argument associated with option */
#endif

#define PRINT_ERROR ((opterr) && (*options != ':'))

#define FLAG_PERMUTE    0x01    // permute non-options to the end of argv
#define FLAG_ALLARGS    0x02    // treat non-options as args to option "-1"
#define FLAG_LONGONLY   0x04    // operate as getopt_long_only

            // return values
#define BADCH       (int)'?'
#define BADARG      ((*options == ':') ? (int)':' : (int)'?')
#define INORDER     (int)1

#define EMSG        ""

#ifdef GNU_COMPATIBLE
#define NO_PREFIX   (-1)
#define D_PREFIX    0
#define DD_PREFIX   1
#define W_PREFIX    2
#endif

            static int getopt_internal(int, char *const *, const char *, const Option *, int *, int);
            static int parse_long_options(char *const *, const char *, const Option *, int *, int, int);
            static int gcd(int, int);
            static void permute_args(int, int, int, char *const *);

            static const char *place = EMSG; /* option letter processing */

            /* XXX: set optreset to 1 rather than these two */
            static int nonopt_start = -1; /* first non option argument (for permute) */
            static int nonopt_end = -1;   /* first option after non options (for permute) */

            /* Error messages */
            static const char recargchar[] = "option requires an argument -- %c";
            static const char illoptchar[] = "illegal option -- %c"; /* From P1003.2 */
#ifdef GNU_COMPATIBLE
            static int dash_prefix = NO_PREFIX;
            static const char gnuoptchar[] = "invalid option -- %c";

            static const char recargstring[] = "option `%s%s' requires an argument";
            static const char ambig[] = "option `%s%.*s' is ambiguous";
            static const char noarg[] = "option `%s%.*s' doesn't allow an argument";
            static const char illoptstring[] = "unrecognized option `%s%s'";
#else
            static const char recargstring[] = "option requires an argument -- %s";
            static const char ambig[] = "ambiguous option -- %.*s";
            static const char noarg[] = "option doesn't take an argument -- %.*s";
            static const char illoptstring[] = "unknown option -- %s";
#endif

            /*
             * Compute the greatest common divisor of a and b.
             */
            static int
            gcd(int a, int b)
            {
                int c;

                c = a % b;
                while (c != 0)
                {
                    a = b;
                    b = c;
                    c = a % b;
                }

                return (b);
            }

            /*
             * Exchange the block from nonopt_start to nonopt_end with the block
             * from nonopt_end to opt_end (keeping the same order of arguments
             * in each block).
             */
            static void
            permute_args(int panonopt_start, int panonopt_end, int opt_end,
                         char *const *nargv)
            {
                int cstart, cyclelen, i, j, ncycle, nnonopts, nopts, pos;
                char *swap;

                /*
                 * compute lengths of blocks and number and size of cycles
                 */
                nnonopts = panonopt_end - panonopt_start;
                nopts = opt_end - panonopt_end;
                ncycle = gcd(nnonopts, nopts);
                cyclelen = (opt_end - panonopt_start) / ncycle;

                for (i = 0; i < ncycle; i++)
                {
                    cstart = panonopt_end + i;
                    pos = cstart;
                    for (j = 0; j < cyclelen; j++)
                    {
                        if (pos >= panonopt_end)
                            pos -= nnonopts;
                        else
                            pos += nopts;
                        swap = nargv[pos];
                        /* LINTED const cast */
                        ((char **) nargv)[pos] = nargv[cstart];
                        /* LINTED const cast */
                        ((char **)nargv)[cstart] = swap;
                    }
                }
            }

            /*
             * parse_long_options --
             *  Parse long options in argc/argv argument vector.
             * Returns -1 if short_too is set and the option does not match long_options.
             */
            static int
            parse_long_options(char *const *nargv, const char *options,
                               const Option *long_options, int *idx, int short_too, int flags)
            {
                const char *current_argv;
                char *has_equal;
#ifdef GNU_COMPATIBLE
                const char *current_dash;
#endif
                size_t current_argv_len;
                int i, match, exact_match, second_partial_match;

                current_argv = place;
#ifdef GNU_COMPATIBLE
                switch (dash_prefix)
                {
                case D_PREFIX:
                    current_dash = "-";
                    break;
                case DD_PREFIX:
                    current_dash = "--";
                    break;
                case W_PREFIX:
                    current_dash = "-W ";
                    break;
                default:
                    current_dash = "";
                    break;
                }
#endif
                match = -1;
                exact_match = 0;
                second_partial_match = 0;

                optind++;

                if ((has_equal = (char *)strchr(current_argv, '=')) != NULL)
                {
                    /* argument found (--option=arg) */
                    current_argv_len = has_equal - current_argv;
                    has_equal++;
                }
                else
                    current_argv_len = strlen(current_argv);

                for (i = 0; long_options[i].name; i++)
                {
                    /* find matching long option */
                    if (strncmp(current_argv, long_options[i].name,
                                current_argv_len))
                        continue;

                    if (strlen(long_options[i].name) == current_argv_len)
                    {
                        /* exact match */
                        match = i;
                        exact_match = 1;
                        break;
                    }
                    /*
                     * If this is a known short option, don't allow
                     * a partial match of a single character.
                     */
                    if (short_too && current_argv_len == 1)
                        continue;

                    if (match == -1)        /* first partial match */
                        match = i;
                    else if ((flags & FLAG_LONGONLY) ||
                             long_options[i].type !=
                             long_options[match].type ||
                             long_options[i].flag != long_options[match].flag ||
                             long_options[i].val != long_options[match].val)
                        second_partial_match = 1;
                }
                if (!exact_match && second_partial_match)
                {
                    /* ambiguous abbreviation */
                    if (PRINT_ERROR)
                        warnx(ambig,
#ifdef GNU_COMPATIBLE
                              current_dash,
#endif
                              (int)current_argv_len,
                              current_argv);
                    optopt = 0;
                    return (BADCH);
                }
                if (match != -1)        /* option found */
                {
                    if (long_options[match].type == Option::NO_ARG
                            && has_equal)
                    {
                        if (PRINT_ERROR)
                            warnx(noarg,
#ifdef GNU_COMPATIBLE
                                  current_dash,
#endif
                                  (int)current_argv_len,
                                  current_argv);
                        /*
                         * XXX: GNU sets optopt to val regardless of flag
                         */
                        if (long_options[match].flag == NULL)
                            optopt = long_options[match].val;
                        else
                            optopt = 0;
#ifdef GNU_COMPATIBLE
                        return (BADCH);
#else
                        return (BADARG);
#endif
                    }
                    if (long_options[match].type == Option::REQUIRED_ARG ||
                            long_options[match].type == Option::OPTIONAL_ARG)
                    {
                        if (has_equal)
                            optarg = has_equal;
                        else if (long_options[match].type == Option::REQUIRED_ARG)
                        {
                            /*
                             * optional argument doesn't use next nargv
                             */
                            optarg = nargv[optind++];
                        }
                    }
                    if ((long_options[match].type == Option::REQUIRED_ARG)
                            && (optarg == NULL))
                    {
                        /*
                         * Missing argument; leading ':' indicates no error
                         * should be generated.
                         */
                        if (PRINT_ERROR)
                            warnx(recargstring,
#ifdef GNU_COMPATIBLE
                                  current_dash,
#endif
                                  current_argv);
                        /*
                         * XXX: GNU sets optopt to val regardless of flag
                         */
                        if (long_options[match].flag == NULL)
                            optopt = long_options[match].val;
                        else
                            optopt = 0;
                        --optind;
                        return (BADARG);
                    }
                }
                else            /* unknown option */
                {
                    if (short_too)
                    {
                        --optind;
                        return (-1);
                    }
                    if (PRINT_ERROR)
                        warnx(illoptstring,
#ifdef GNU_COMPATIBLE
                              current_dash,
#endif
                              current_argv);
                    optopt = 0;
                    return (BADCH);
                }
                if (idx)
                    *idx = match;
                if (long_options[match].flag)
                {
                    *long_options[match].flag = long_options[match].val;
                    return (0);
                }
                else
                    return (long_options[match].val);
            }

            /*
             * getopt_internal --
             *  Parse argc/argv argument vector.  Called by user level routines.
             */
            static int
            getopt_internal(int nargc, char *const *nargv, const char *options,
                            const Option *long_options, int *idx, int flags)
            {
                const char *oli;                /* option letter list index */
                int optchar, short_too;
                int posixly_correct;    /* no static, can be changed on the fly */

                if (options == NULL)
                    return (-1);

                /*
                 * Disable GNU extensions if POSIXLY_CORRECT is set or options
                 * string begins with a '+'.
                 */
                posixly_correct = (getenv("POSIXLY_CORRECT") != NULL);
#ifdef GNU_COMPATIBLE
                if (*options == '-')
                    flags |= FLAG_ALLARGS;
                else if (posixly_correct || *options == '+')
                    flags &= ~FLAG_PERMUTE;
#else
                if (posixly_correct || *options == '+')
                    flags &= ~FLAG_PERMUTE;
                else if (*options == '-')
                    flags |= FLAG_ALLARGS;
#endif
                if (*options == '+' || *options == '-')
                    options++;

                /*
                 * XXX Some GNU programs (like cvs) set optind to 0 instead of
                 * XXX using optreset.  Work around this braindamage.
                 */
                if (optind == 0)
                    optind = optreset = 1;

                optarg = NULL;
                if (optreset)
                    nonopt_start = nonopt_end = -1;
start:
                if (optreset || !*place)        /* update scanning pointer */
                {
                    optreset = 0;
                    if (optind >= nargc)            /* end of argument vector */
                    {
                        place = EMSG;
                        if (nonopt_end != -1)
                        {
                            /* do permutation, if we have to */
                            permute_args(nonopt_start, nonopt_end,
                                         optind, nargv);
                            optind -= nonopt_end - nonopt_start;
                        }
                        else if (nonopt_start != -1)
                        {
                            /*
                             * If we skipped non-options, set optind
                             * to the first of them.
                             */
                            optind = nonopt_start;
                        }
                        nonopt_start = nonopt_end = -1;
                        return (-1);
                    }
                    if (*(place = nargv[optind]) != '-' ||
#ifdef GNU_COMPATIBLE
                            place[1] == '\0')
                    {
#else
                            (place[1] == '\0' && strchr(options, '-') == NULL))
                    {
#endif
                        place = EMSG;       /* found non-option */
                        if (flags & FLAG_ALLARGS)
                        {
                            /*
                             * GNU extension:
                             * return non-option as argument to option 1
                             */
                            optarg = nargv[optind++];
                            return (INORDER);
                        }
                        if (!(flags & FLAG_PERMUTE))
                        {
                            /*
                             * If no permutation wanted, stop parsing
                             * at first non-option.
                             */
                            return (-1);
                        }
                        /* do permutation */
                        if (nonopt_start == -1)
                            nonopt_start = optind;
                        else if (nonopt_end != -1)
                        {
                            permute_args(nonopt_start, nonopt_end,
                                         optind, nargv);
                            nonopt_start = optind -
                                           (nonopt_end - nonopt_start);
                            nonopt_end = -1;
                        }
                        optind++;
                        /* process next argument */
                        goto start;
                    }
                    if (nonopt_start != -1 && nonopt_end == -1)
                        nonopt_end = optind;

                    /*
                     * If we have "-" do nothing, if "--" we are done.
                     */
                    if (place[1] != '\0' && *++place == '-' && place[1] == '\0')
                    {
                        optind++;
                        place = EMSG;
                        /*
                         * We found an option (--), so if we skipped
                         * non-options, we have to permute.
                         */
                        if (nonopt_end != -1)
                        {
                            permute_args(nonopt_start, nonopt_end,
                                         optind, nargv);
                            optind -= nonopt_end - nonopt_start;
                        }
                        nonopt_start = nonopt_end = -1;
                        return (-1);
                    }
                }

                /*
                 * Check long options if:
                 *  1) we were passed some
                 *  2) the arg is not just "-"
                 *  3) either the arg starts with -- we are getopt_long_only()
                 */
                if (long_options != NULL && place != nargv[optind] &&
                        (*place == '-' || (flags & FLAG_LONGONLY)))
                {
                    short_too = 0;
#ifdef GNU_COMPATIBLE
                    dash_prefix = D_PREFIX;
#endif
                    if (*place == '-')
                    {
                        place++;        /* --foo long option */
#ifdef GNU_COMPATIBLE
                        dash_prefix = DD_PREFIX;
#endif
                    }
                    else if (*place != ':' && strchr(options, *place) != NULL)
                        short_too = 1;      /* could be short option too */

                    optchar = parse_long_options(nargv, options, long_options,
                                                 idx, short_too, flags);
                    if (optchar != -1)
                    {
                        place = EMSG;
                        return (optchar);
                    }
                }

                if ((optchar = (int) * place++) == (int)':' ||
                        (optchar == (int)'-' && *place != '\0') ||
                        (oli = (const char *)strchr(options, optchar)) == NULL)
                {
                    /*
                     * If the user specified "-" and  '-' isn't listed in
                     * options, return -1 (non-option) as per POSIX.
                     * Otherwise, it is an unknown option character (or ':').
                     */
                    if (optchar == (int)'-' && *place == '\0')
                        return (-1);
                    if (!*place)
                        ++optind;
#ifdef GNU_COMPATIBLE
                    if (PRINT_ERROR)
                        warnx(posixly_correct ? illoptchar : gnuoptchar,
                              optchar);
#else
                    if (PRINT_ERROR)
                        warnx(illoptchar, optchar);
#endif
                    optopt = optchar;
                    return (BADCH);
                }
                if (long_options != NULL && optchar == 'W' && oli[1] == ';')
                {
                    /* -W long-option */
                    if (*place)         /* no space */
                        /* NOTHING */;
                    else if (++optind >= nargc)     /* no arg */
                    {
                        place = EMSG;
                        if (PRINT_ERROR)
                            warnx(recargchar, optchar);
                        optopt = optchar;
                        return (BADARG);
                    }
                    else                /* white space */
                        place = nargv[optind];
#ifdef GNU_COMPATIBLE
                    dash_prefix = W_PREFIX;
#endif
                    optchar = parse_long_options(nargv, options, long_options,
                                                 idx, 0, flags);
                    place = EMSG;
                    return (optchar);
                }
                if (*++oli != ':')              /* doesn't take argument */
                {
                    if (!*place)
                        ++optind;
                }
                else                /* takes (optional) argument */
                {
                    optarg = NULL;
                    if (*place)         /* no white space */
                        optarg = place;
                    else if (oli[1] != ':')     /* arg not optional */
                    {
                        if (++optind >= nargc)      /* no arg */
                        {
                            place = EMSG;
                            if (PRINT_ERROR)
                                warnx(recargchar, optchar);
                            optopt = optchar;
                            return (BADARG);
                        }
                        else
                            optarg = nargv[optind];
                    }
                    place = EMSG;
                    ++optind;
                }
                /* dump back option letter */
                return (optchar);
            }

#if 0
#ifdef REPLACE_GETOPT
            /*
             * getopt --
             *  Parse argc/argv argument vector.
             *
             * [eventually this will replace the BSD getopt]
             */
            int
            getopt(int nargc, char *const *nargv, const char *options)
            {

                /*
                 * We don't pass FLAG_PERMUTE to getopt_internal() since
                 * the BSD getopt(3) (unlike GNU) has never done this.
                 *
                 * Furthermore, since many privileged programs call getopt()
                 * before dropping privileges it makes sense to keep things
                 * as simple (and bug-free) as possible.
                 */
                return (getopt_internal(nargc, nargv, options, NULL, NULL, 0));
            }
#endif /* REPLACE_GETOPT */
#endif

            /*
             * getopt_long --
             *  Parse argc/argv argument vector.
             */
            int
            getOption(int nargc, char *const *nargv, const char *options,
                      const Option *long_options, int *idx)
            {

                return (getopt_internal(nargc, nargv, options, long_options, idx,
                                        FLAG_PERMUTE));
            }

            /*
             * getopt_long_only --
             *  Parse argc/argv argument vector.
             */
            int
            getOptionSingle(int nargc, char *const *nargv, const char *options,
                            const Option *long_options, int *idx)
            {

                return (getopt_internal(nargc, nargv, options, long_options, idx,
                                        FLAG_PERMUTE | FLAG_LONGONLY));
            }

            ///////////////////////////////////////////////////////////////////////////////

        }
    }
} // namespace mp4v2::platform::prog
